Collectible Card Game Headquarters

Describe the Bug:
Blanket of Night's controller's opponent can't tap his/her lands to add to his/her mana pool (unless, of course, they were already able to produce before Blanket entered the battlefield.

Said opponents lands are considered Swamps by cards like Karma, though.

Which card did behave improperly ?
Blanket of Night

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
KOT, duel

What exactly should be the correct behavior/interaction ?
Blanket of Night's controller's opponent can tap his/her lands to add to his/her mana pool (e.g. by means of a legacy card).

Are any other cards possibly affected by this bug ?
Same for Urborg, Tomb of Yawgmoth

Can't repro the exact functioning as they required legacy card for this kind of effects can't produce mana for hardcoded reasons.

So does this mean this is an engine limitation that can't be solved?

Yup.